Projection of stereoscopic images



Mardi 2, 1948- E. H. WRIGHT PROJECTION OF STEREOSCOPIQYIMAGES Filed June 5, 1945 /we/vme /f' WP/G/fr Bx Megas@ Arme/ffy.:

Patented Mar. 2, 1948 UNITED STATES PATENT OFFICE Edwin Herbert Wright, Farnham Common, England Application June 5, 1946, Serial No. 674,481 In Great Britain September 1, 1945 2 Claims. (C1. Silvie-6) This invention relates to systems for the proiection of stereoscopic cinematograph images.

Various systems involving the use of pclarised iight have been suggested but those systems of which I am aware have either required the pro duction of a special type of lm, have necessiiated some important alterations in the projector mechanism, or have involved an optical device which required to be coupled up with the projector mechanism. The principal object of the present invention is to provide a projection system which overcomes all these disadvantages and involves no more than the insertion of simple optical devices between the light source and the film gate and in front of the objective.

According to the invention, a system for the projection of stereoscopic cinematograph images consisting of left and right eye-view images arranged side-by-side on successive frames on a single width nlm, comprises means disposed between the light source and the nlm for dividing the light beam into two parallel beams polarised in planes mutually at right angles whereby the side-by-side left and right eye-view images are projected by the respectively polarised beams, and means for superimposing the thus projected images on the screen. I

A suitable means for dividing the light beam into two parallel beams polarised in planes mutually at right angles is described in the specification of my co-pending application No. 584,281 with reference to Figure 2.

A simple bi-prism may conveniently be used for superimposing the pair of stereoscopic images on the screen.

The system can readily be converted in known manner to operate with clrcularly polarised light by the lnterposltion o! a quarter wave retardation plate at any suitable point ln the light beam.

One embodiment o! the invention will now be described by way of example with reference to the accompanying diagrammatic drawing which is partly in plan and partly in elevation.

The light beam A of the projector is caused to strike a polarising device B of the kind described in the specicatlon of my co-pendins application No. 584,281 with reference to Figure 2. Buch a polarlslng device provides a polarlsed beam C and a parallel beam D polarisedl in a plane at right angles to the plane of the polarlsed i?, beam C. The polarised beams C and I3 are utilised te project pairs of stereoscopic images arranged. side-bysi' ie on successive frames ci a singlecvidth film. Such a pair of images are 5 indicated at F and G, it being understood that the polarising device and the lm are Viewed` in plan with the film passing through the plane of the paper. After passing through the usual objective H, the images are superimposed on the screen J by means ci the simple bi-prism K, the objective H and loi-prism K being viewed in elevation.

In order that the images may be viewed stereoscopically it is merely necessary to provide analysers with planes of polarisation corresponding with those produced by the polariser B to ensure that the respective eye-view images are received only by the appropriate eye.

I claim:

1. A system for the projection by means of a single light beam of stereoscopic cinematograph images consisting of left and right eye-view images arranged side-by-side on successive frames on a single width nlm, comprising means disposed in said beam between the light source and the nlm for dividing said beam into two parallel and contiguous beams polarized in planes mutually at right angles, said polarized beams passing through the left and right eye-view 3 images respectively, a single objective and means for superimposlng the respective eye-view images on the screen.

2. A system according to claim 1, wherein the means for superimposing the images on the screen consists of a bi-prism.

EDWIN HERBERT WRIGHT.

REFERENCES CITED The following references are of record in the ille ot this patent:

UNITED STATES PATENTS Number Name Date 1,503,786 Pictet et al. Aug. 5. 1924 FOREIGN PATENTS Number Country Date 224,393 Great Britain Nov. 13, 1924 519,488 Great Britain Mar. 28, 1940 

